1. Field of the Invention
The present invention relates to an ink jet recording sheet which is equipped with an ink accepting layer on a substrate. In particular, the present invention pertains to the ink jet recording sheet which is excellent in scratch-abrasion resistance under wet conditions and besides in image density, and in which the ink accepting layer is excellent in water resistance and adhesion strength.
2. Description of the Related Arts
In recent years, an ink jet recording system as one of image printing systems has expanded the fields of application by virtue of such advantages that high quality images are obtained with ease and the running cost is relatively low. In particular, there are steadily increasing demands on printing full-color images for use as a poster and the like. In the case of printing full-color images, an ink accepting layer having a relatively large thickness is required by reason of a sufficient ink absorption capacity being called upon.
However, since the liability to peeling off of the ink accepting layer increases with an increase in the thickness of the aforesaid layer, it is necessary to enhance the strength of adhesion to the substrate. Thus for the purpose of enhancing the strength of adhesion to the substrate, it is a customary practice to install an anchor coat layer between the substrate and the layer which is subjected to ink jetting. Nevertheless, the present situation is such that the working effect from the anchor coat layer is not satisfactory.
Moreover in the purpose of use as a poster or the like, the job of placing a notice outdoors is sometimes carried out in the rain, and accordingly the ink jet recording sheet is called upon to have not only water resistance but also scratch-abrasion resistance under wet conditions. Further in the case of a poster, importance is attached to image impression and its appealing power, and thereby the image is required to have a high density. However, nothing has hitherto been found which simultaneously satisfies both the requirements as mentioned above.
On the other hand, as a means for increasing the ink absorption capacity there is described in Japanese Patent Application Laid-Open No. 147361/1999 (Heisei 11), an ink jet recording body in which cracks are provided on at least one layer of lower layers other than a surface layer, and also disclosed therein a technique of filling in the cracks with a solvent or water and thereafter applying coating to form an upper layer.
Nevertheless, the above-mentioned ink jet recording body suffers from such drawback as low strength of adhesion between the lower layer having cracks and the upper layer in spite of its excellent ink absorption capacity.